Various Internet protocols are known for authenticating and encrypting communications between devices communicating over the Internet. These protocols may operate at different Internet abstraction layers. For example, various protocols that operate at the Application layer, the Transport layer, the Internet layer, or the Link layer are known. Protocols that operate at one or more of these abstraction layers may be used in a variety of applications including web browsing, electronic mail, Internet faxing, instant messaging, and Internet Protocol (IP) telephony.